Apparatus for advancing film



May 19, 1936. G G M REN 2,041,011

I APPARATUS FOR ADVANCIHG FILM I Filed May 22, 1934 2 Sheets-She et 1lnvenmr "f l 3f Z0 50 May 19, 1936. G, gb o 2,041,011

APPARATUS FOR ADVANCING FILM Filed May 22, 1954 2 Sheets-Sheet 2Inventor Ldtlorney;

Patented May 19, 1936 UNITED- STATES PAT E'ZNT'T or-Frc-E 2,041,011APPARATUS FOR' ADvANoiNG" F I II M GabrielGar'cia Moreno, LosAngelesQ-Qalif; as-

signor', by direct and mesn'e assignments; to C Corporation; New York,N. Y.,' a corporation of Delaware rat-catama- 2'231934, Serial' No.726,834

6Claims. (o1. ss*-1s.2)

This inventionrelate'sfto'a newarid improved method Of" intermittentlyadvaiicihg strip film bearing photographic recor s of images, sound,etc. The'invention alsorelates' to avsirnple and 5' efiicientarrangement and combination of ele? camera's; projectors, printers;andother filmtreating machines utilizing" intermittent move: ment, maybe readily adapted to the performance treated, suitable and readilyapparent modifica -j tions' being made in the size 'and'configuration ofthe illustrative form of apparatus" nerein ue': scribed for the purposeof adapting the same to difierent forms'of strip film. 7

Normally, whenever it is' desired" to intermit tently advance 35millimeter intermittent sprocke'tshaving a diameteroi about 2 1'millimeters and carrying 16 teeth" are us'edk Such intermittent drivesprockets are diwgna any suitable m'ann'er as, rorexamp ayme he of a--star cam or Venetian moveni'ent ues 'ned; to'

" longitudinallyadvance the film-a dist lent to theheightoija'nornialirairiea about 18.9 millimeters; whenit 'ide'sired tochange the length of film intermittently advanced, it has'been'thoughtnecessary to change the entire intermittent movement;including-star cam; etc'., orto increase thesize'bf the'intermittentsprocket and gearit to existing inter mittent drive shaft so' astoin'creaise the;pe'ripheral speed of length of film advanced by" thesprocketi For example; a co-pendingapplication filed by me describes amethod of projecting cinematographic-films in which it is desired tointermitt'ently advance the'film longitudinally adista'hce twice" thatadvanced'duringnormal projection'or photography. It has been found,however; that when-the driving sprocke't is enlarged andgeared to theexisting-drive shaft; the relationship-betw'een shutter speeds filmspeed,

or shutter speeds-and'periods of movement and rest ofthe film, aresubstantially changed so that properpro'jecting orphotographingconditions do not existr Furthermore, it is to bereniembered that inthe-normal-intermittent drive means used-heretofore,the film isc'onstantly inco-ntact with the intermittently drivensprocketand" there is a ten: dency for mechanica'l'vibrations to betrarisir'iittedl; to the film. In a co-pending pucatimisenar No.706,839; an apparatus for ir itermittentlyatl- 5' va'nc'irigstrip' filmhas beende scribedwhich so essome of these diflicultiesfTh'prese'rit'applica tion' may be said to be a continuation impart ofthe prior application Serial No, 706,339.

I have discoveredthat"iri'order tojprevent lon 10- gitudinal movement ofthe fi mwithinthe film gate, it is necessary to mainta'm the'variousunits composing the intermittent movement andiadja; centelements inja'd efinite relationship to one another."Asher'einafter'described in detail, it has 5 been found necessary tomaintairi' thefilm in substantially a single plane during-itspassagethrough the film gate under the influence of the intermittentlydriven sprockets.

The present invention therefore relates to Iim provements in devices forintermittently advancing strip film whereby the film is -maintained in"a stationary and positively registered position without the usej'ofseparate registering-means;

Ari obje'ctof this invention is to disclose and 25 provide a' method ofintermittentlyadvancing strip film longitudinally inwhich the film; ismoved transversely into an'dout of engagement with a combined drivingandregistering sprocket;

Another object" isto disclose and" providea sprocket construction whichintermittently moves fiim l neou r e is rsjihtfi m v K'furtherobi e'ctis to disclose and provide an arrangement of" elements" whereby film;may be intermittently advanced'in an efiicient mariner on 35 existingtypes of film treating machines withbut a minimum" amountof 'mechanicalchange in existing forms of apparatus.

These and other objects, uses'and advantages of the'inventiorr"-willbecorrfe apparent to those 40 skilled in thea'rtirom-the following detailed description of a"-'preferred'me'thod' ofcarryingiout the invention' and an illustrative form of apparatus whichmaybe used in the per'formanc'e of the method. 45

guide and intermittent sprocket} 50 r Fig; '2 is av'erticalsectiontakeii'abngtheplane II-II indicated mites-1.

Fig. 3 is a vertical sectiono'rafl=portionof the device shovvnin Fig; 1,the section bein'g' =talieh through" a plane indicated at 'III -III inFig gl. 5

Fig. 4 is a front elevation of'the film-controlling device or guide withone of the shoes in position-for the insertion of film.

Fig. 5 is a transverse section taken along the 7 plane V-V indicated inFig. 4. r V d Fig. 6 is an enlarged view, partly diagrammatic,

showing the relationship between the teeth of the sprocket and the, filmwhen the film is in driving and registering. engagement with the teeth.

Inthe drawings a double gate is shown whereby two adjacent frames ofstrip film may be simultaneously projected. The film. is generallyindicated by the numeral I and extends through the gate member 2 betweenlongitudinal guide rails 3 and '4. The gate 2 is preferably longer thannormal gates so that a greater length of film is held in contact withthe gate and between the guide rails 3 and lthan is generally the case.-The film passes in front of the apertures 5 and 6 through whichprojection is had. The film is yieldably pressed against the gate 2 bymeans of a pressure plate, generally indicated at and lower pressurerails 8 and 9 respectively,

1, which is shown spaced away from the gate properin Fig. 2. r

The pressure plate 1 is provided with upper these pressure rails beingyieldably urged against the edge portions of the film by means of railsprings IO, N and I2. The member |3 carried by the pressure plateis ahorizontally extending non-reflecting member which leads to the lensesthrough which projection is had, thereby preventing the'upper lens fromprojecting the image in the lower gate 6, and vice versa. The pressureplate 1, wheninuse, is held against the mm in the gate 2. need not bedescribed in detail as they are common to the art. i

"The means for intermittently advancing and registering the film Icomprise a sprocket l5 "mounted upon a shaft l6 which normally carriesan intermittent sprocket in camera's, printers,

etc. The normal sprocket, however, is provided with 16 teeth whereas thesprocket I5 is provided 7 with 32 teeth. No change is made in theordinary intermittent movement which drives the shaft 5.

advances the'film longitudinally a distance equivalent to the height ofone picture area, is utilized in driving the shaft, 6.

In view of the fact that the sprocket I5 is provided with 32 teeth, thenin the event the film I was maintained in continuous engagement with thesprocket |5,.it would be longitudinally advanced a distance equivalentto the height of two adjacent picture areas during each period ofmovement. -In the event the film l was constantly maintained inengagement with the sprocket |5, it would be caused to travel throughthe camera or printer attwice the speed of normalfilm so that 48 frameswould pass the film the p ane assumed by the film l in the gate 2 Thespecific means used for this purpose In other words, the same movement.which normally causes a partial rotation of a driving sprocket(provided with 16 teeth) and 2,041,011 V that the film lies in a planesubstantially tan- 7 gential to the root diameter of the sprocket IE orthe plane of the film in the gate 2 when extended intercepts athree-tooth segment of said sprocket. The sprocket l5, furthermore,consists of two spaced sprocket wheels (as shown in Fig. 1), the

width of the sprocket wheels at points adjacent the peripheriesthereofbeing substantially equal to the width of the teeth carried by thesprocket wheels. These teeth I 1, I8, |9,-etc., (shown more particularlyin Fig. 6) are prismatic in form, having a height only very'slightly in'excess of the normal thickness of the film, say a height of 0.025inches. Moreover, the teeth l1, l8, l9, etc., preferably have a rootlength substantially equivalent to the height of the film perforationsso as to completely fillfthe perforations. having perforations 0.0787inches high is used, the teeth should have a 'root length of about0.0785 inches. The teeth need not be of a width sumcient to completelyfill the perforation, however.

The film control'device, generally indicated at.

20, comprises a guide member 2| pivoted at a point near the gatedischarge, the center of the pivot lying in the plane of the film withinthe gate.

.25 The film control device is adapted to in- V termittently move thefilm into and out of regis-' tering and driving engagement with thesprock-.

et I5.

The guide 2| maybe provided with pivot pins 22 and 23 journaled in ears24 and25 depending I from the gate 2. The inner surface of the guide 2|,indicated at 26, should be positioned but; slightly to one side of aplane passing through the axes of the pivots 22 and 23 so that such axespass directly'through thecenter of film extending from the gate 2 intothe guide 2|.

When

the shoe 2| pivots on the pins 22 and 23, a bending movement is impartedto the film only. within the shoe 2| so that fluttering or longitudinalmotion of the film within the gate 2 does not occur..

Attention is called to the fact that the shoe 2| Preferably, as

curved portion, the radius of curvature being sub- Istantially'equivalent to the radius of the sprocket IS. The guide [I hasa longitudinally extending central depression and side shoulders 21 and21*.

which contact with the edge portions of the film,

the picture area of the filmbeing maintained out. of contact with theguide 2|. Longitudinally di-, rected apertures 28 and 29 are formed inthe shoulders 21 and 21 respectively, these apertures being adapted toreceive three or four of the l teeth carried by the sprocket l5. r

, The side portions of the guide 2| are provided with shoes 30 and 3|which extend over the edge areas of the film passing through the guide2|. These shoes 30 and 3| are yieldably urged against the bosses oredge'portions 21,and 21 of the guide 2|,by means'of, light springs 32and r 33 carried by bolts 34 and 35. 'The shoe 3|] is not transverselymovable on the guide 2| and a the shoe 3| is provided with transverseapertures 36 through which the bolt 35 extends, so that the shoe 3| canbe moved transversely into the position shown in Figs. 4 and 5. Theshoes 30 and 3| may be provided. with longitudinal slots 31 and 38respectively, in order to' provide proper teeth I1, I 8,

clearance for the outer ends of the IS, etc., of the sprocket I5. 7

Means are also provided for' moving the carried by the guide 2| intoand, out of engagement. with the; teeth of the intermittently drivensprocket 5 in timed relation to periods of movement of said sprocket.Such means may include a shaft 48 which is usually found in allfilmhandling machines such as cameras, projectors, etc.,, in theposition with respect to the intermittently driven sprocket shaft Itshown in Fig. 2;. This shaft normally rotates at four times the speed ofthe shaft 56. Under such conditions, an elliptical or two-lobed cam 4|is mounted in the shaft 40.

Theguide 2| is provided with an arm 42 which carries an adjustable shoe43 carried by the end of a threaded shaft 44 which may be looked uponthe rib of the arm 42' by means of the lock nut 45. The shoe43-is heldagainst the surface of the cam 4| by means of aspring 41 connecting thearm 42 with a stationary object, such as the eye-bolt 48 attached to asuitable portion of the frame of the camera, projector, or other machinein which the device is installed.

In operation of the device described hereinabove, the film is threadedthrough the film gate 2 and through the film-controlling device 20' bytransversely adjustably positioning the shoe 3|. and inserting the filminto the guide so that it is yieldingly held between the shoulder 2'!and the shoe 30 and rests upon the shoulder 21. The shoe-3 is then movedinto position so as to yield ably hold the edge portion of the film onthe shoulder 21. idler rollers or sprockets, take-up rollers, etc., ofother portions of the film-treating machine, these additional elementsnot being shown on the drawings. The pressure plate 1 is then moved intooperating relation with the film gate 2 and the drive mechanism startedso as to intermittently drive the sprocket l5. The film control device20 will be intermittently pivoted upon the pins 22 and 23 by reason ofthe cam 4|. The film within the guide 2| will be brought into engagementand register with the teeth of the sprocket 5 when the sprocket is atrest. Because of the configuration of the teeth, the teeth act asregistering pins as well as driving elements. While in such engagement,the sprocket I5 will be partially rotated, thereby longitudinallyadvancing the film I a distance equivalent to precisely two frames ofthe film. At the end of such intermittent movement, the spring I5 comesto rest, the film being in proper registered position. Thereafter, theguide 2| is again pivoted on its pins, moving the film out of engagementwith the teeth of the sprocket, this outward movement being caused bythe revolution of the cam 4| and the pull on the spring 41. During suchperiod of rest, projection of the images carried by the film andpositioned in the gates 5 and 5 may take place. During such period, whenthe film is stationary, the sprocket I5 will perform another partialrotation but such rotation will not cause a longitudinal movement of thefilm because the film is not in engagement with the teeth of thesprocket. This free intermittent movement is due to the fact that theshaft I5 is intermittently driven by the driving mechanism which isnormally employed on all strip film machines adapted to advance the filmone frame at a time. At the conclusion of this free partial rotation ofthe sprocket I5, the cam 4| again advances or pivots the guide 2|against the driving sprocket l5, whereupon the cycle of operations canbe repeated.

During the pivoting of the guide 2|, any bend- The film is then passedover theing. which takes. 'place in the film occurs either along an axispassing directly through the film or. along the slight curvatureintermediate the ends. of the guide 2|. Inasmuch as the. film isyieldingly held between the guide 2| and the shoes 30 and 3| along suchcurvedpath', no longitudinal movement takes place because of the bendingor pivoting movement of. the guide: 2|. The pressure rails B and 9. ofthe gate 2 also assist in maintaining the film against longitudinalmovement. The. side guide rails'3 and 4 of the gate effectively preventtransverse movement of: the film within the gate2.

It is to be understood that the guide 2| may be oscillated on its pivotsin any suitable manner. The size and configuration of the cam 4| dependsupon the speed of rotation of the shaft. it with respect to the speed ofthe shaft IE on which the sprocket I5 is mounted. The construction ofthe guide 2| may be materially changed, it being highly desirable,however, that the guide 2| maintain the film approximately in anextension of the plane occupied by the film in the gate 2;

Those skilled in the art'will appreciate that numerous modifications andadaptations of this invention may be made and all such changes andmodifications as come within the scope of the appended claims areembraced thereby.

I claim: r

1. In an apparatus forintermittently advancing film, the combination ofan intermittently driven sprocket provided with teeth of prismatic formhaving a root length substantially equiva-- lent to the height of filmperforations; a'film gate provided with side guide rails adapted. to-

a film control device positioned between the film gate and sprocket,said film control device being pivoted at a point near the gatedischarge, the center of the pivot lying in the plane of the film, saidfilm control device being adapted to slidably receive film discharged bysaid gate, and means for moving said film control device on its pivot intimed relation to periods of movement of said sprocket to periodicallymove the film into and out of driving engagement with saidintermittently driven sprocket.

2. In an apparatus for intermittently advancing strip filmlongitudinally, the combination of an intermittently driven sprocket; afilm gate adapted to movably receive strip film, said film gate lying ina plane intercepting a three-tooth segment of said sprocket; a filmcontrol device comprising a guide pivotally positioned between the filmgate and sprocket and lying substantially in an extension of the planeof the film in the gate, said guide being pivoted on an axis near thegate discharge and with its center in the plane of the film in said gateand provided with a curved portion including an arc of about three teethon said sprocket, and means for moving said guide on its pivot in timedrelation to periods of movement of said driven sprocket to periodicallymove the film into and out of engagement with said intermittently drivensprocket.

3. In an apparatus for intermittently advancing strip filmlongitudinally, the combination of an intermittently driven sprocket, afilm gate the film gate and sprocket and lying substantially in anextension of the plane of the film V in the gate, said guide beingpivoted on an axis near the gate discharge and with its center in theplane of the film in said gate and, provided with a curved portionincluding an arc of about three teethton said sprocket, shoes carried by7 said guide and yieldably pressed thereagainst,

and means for moving said guide on its pivot in timed relation toperiods of movement of said driven sprocket to periodically move thefilm into and out of engagement with said intermittently driven.sprocket.

4. In an apparatus for intermittently advancing stripfilmlongitudinally, the combination of an intermittently driven sprocket, afilm gate adapted to movably receive strip film, said film 'gate lyingin a plane intercepting a three-tooth segment of said sprocket; a filmcontrol device comprising a guide pivotally positioned between the filmgate and sprocket and lying substantially in an'extension of the planeof the film V in the gate, said guide being pivoted on an axis nearthegate discharge and with its center in the-plane of the film in said gateand provided with a curved portion including an arc of about three teethon said sprocket, shoes carried by said guide means for yieldablypressing said shoes against edge portions of film carried by said guide,means ior'transversely adjustably positioning oneof said shoes on saidguide out of contact with film on said guide, and means for moving saidguide on its pivot in timed relation to periods of movement of saiddriven sprocket to periodically move the film into and out of engagementwith said intermittently driven sprocket. V

5. In an apparatus for intermittently advancing strip filmlongitudinally, the combination of an intermittently driven sprocketconsisting of two spaced sprocket wheels provided with teeth ofprismatic form having a root length substantially equivalent. totheheight of film perforations, the width of said sprocket wheels beingequal to the width of the sprocket teeth, said teeth being narrower thanthe width of sprocket holes in said film, a. film gate lying in a planesubstantially tangential to the root diameterof said sprocket, a guidepivoted on an axis with its center in the plane of the film in saidgate, and

means for moving said guide on its pivot in timed relation to periods ofmovement of said sprocket for moving the film into and out ofregistering engagement with said intermittently driven sprocket.

6. In an apparatus for intermittently advancing strip filmlongitudinally, the combination of an intermittently driven sprocketprovided with teeth of prismatic form having a root length substantiallyequivalent to the height of film perforations whereby said sprocket mayengage with strip film and drive and. register the same; a film gateadapted to movably receive strip film, said film gate lying in a planeintercepting a threetooth segment of said sprocket; a film controldevice comprising a guide pivotally positioned between the film gate andsprocket and lying'subsprocket. V

GABRIEL GARCIA MORENO.

'stantially in an extension of the plane of the,

